Portion of a golf club head



FIG. 1 is a perspective view, taken from the bottom, of a portion of a golf club head according to our new design;

FIG. 2 is a rear view thereof; and,

FIG. 3 is a bottom view thereof.

The broken line showing of a golf club head is for illustrated purposes only and forms no part of the claimed design. 

The ornamental design for a portion of a golf club head, as shown and described. 